This invention relates to an automatic defect review and classification system. More specifically, the invention relates to a system that reviews and acquires defect images occurring in a semiconductor production process and classifies the defects in accordance with their kind.
To improve a production yield of semiconductor devices, it is very important to discover in an early stage the defects occurring in the semiconductor production process and to take counter-measures for the defects. The defects that may affect the production yield have become diversified in recent years with miniaturization of semiconductor devices and the number and kind of defects to be confirmed increase.
Therefore, an ADR/ADC defect inspection system having functions of an automatic defect review (hereinafter called “ADR”) for automatically acquiring defect images and an automatic defect classification (hereinafter called “ADC”) for automatically classifying the defects in accordance with their kind on the basis of the defect images acquired has been proposed (refer to JP-A-2001-127129, for example).
In the ADR/ADC system disclosed in the patent document 1 described above, when the defect classification processing by the ADC is not completed before the start of image acquisition of next defects after completion of image acquisition by the ADR, the processing by the ADC becomes a bottleneck and invites the drop of through-put of the entire ADR/ADC system.
Recently, the processing time about the ADR has been gradually reduced through speed-up of a sample stage, improvement of an imaging system such as speed-up of an auto-focus function or by the introduction of a high speed mode that lays stress on the through-put. Therefore, the problem that the processing of the ADC cannot catch up with ADR remains unsolved.